Buggy code:
public static final Object DEFAULT_FACTORY = "DEFAULT" ; protected CompilationUnit ( IPackageFragment parent , String name ) { } public void accept ( IAbstractSyntaxTreeVisitor visitor ) throws JavaModelException { } protected void buildStructure ( OpenableElementInfo info , IProgressMonitor pm ) throws JavaModelException { } public void codeComplete ( int offset , ICompletionRequestor requestor ) throws JavaModelException { } public IJavaElement [ ] codeSelect ( int offset , int length ) throws JavaModelException { } public void commit ( boolean force , IProgressMonitor monitor ) throws JavaModelException { } public void copy ( IJavaElement container , IJavaElement sibling , String rename , boolean force , IProgressMonitor monitor ) throws JavaModelException { } protected OpenableElementInfo createElementInfo ( ) { } public IImportDeclaration createImport ( String name , IJavaElement sibling , IProgressMonitor monitor ) throws JavaModelException { } public IPackageDeclaration createPackageDeclaration ( String name , IProgressMonitor monitor ) throws JavaModelException { } public IType createType ( String content , IJavaElement sibling , boolean force , IProgressMonitor monitor ) throws JavaModelException { } public void delete ( boolean force , IProgressMonitor monitor ) throws JavaModelException { } public void destroy ( ) { } public boolean equals ( Object o ) { } protected boolean equalsDOMNode ( IDOMNode node ) throws JavaModelException { } public IJavaElement [ ] findElements ( IJavaElement element ) { } public IType findPrimaryType ( ) { } public IJavaElement findSharedWorkingCopy ( IBufferFactory factory ) { } public IJavaElement findSharedWorkingCopy ( ) { } protected boolean generateInfos ( OpenableElementInfo info , IProgressMonitor pm , Map newElements , IResource underlyingResource ) throws JavaModelException { } public IType [ ] getAllTypes ( ) throws JavaModelException { } public ICompilationUnit getCompilationUnit ( ) { } public char [ ] getContents ( ) { } public IResource getCorrespondingResource ( ) throws JavaModelException { } public IJavaElement getElementAt ( int position ) throws JavaModelException { } public char [ ] getFileName ( ) { } protected char getHandleMementoDelimiter ( ) { } public IImportDeclaration getImport ( String name ) { } public IImportContainer getImportContainer ( ) { } public IImportDeclaration [ ] getImports ( ) throws JavaModelException { } public char [ ] getMainTypeName ( ) { } public IJavaElement getOriginal ( IJavaElement workingCopyElement ) { } public IJavaElement getOriginalElement ( ) { } public IPackageDeclaration getPackageDeclaration ( String name ) { } public IPackageDeclaration [ ] getPackageDeclarations ( ) throws JavaModelException { } public char [ ] [ ] getPackageName ( ) { } public IPath getPath ( ) { } public IResource getResource ( ) { } public IProblemRequestor getProblemRequestor ( ) { } public String getSource ( ) throws JavaModelException { } public ISourceRange getSourceRange ( ) throws JavaModelException { } public IType getType ( String name ) { } public IType [ ] getTypes ( ) throws JavaModelException { } public IJavaElement getSharedWorkingCopy ( IProgressMonitor pm , IBufferFactory factory , IProblemRequestor problemRequestor ) throws JavaModelException { JavaModelManager manager = JavaModelManager . getJavaModelManager ( ) ; Map sharedWorkingCopies = manager . sharedWorkingCopies ; Map perFactoryWorkingCopies = ( factory == null ) ? ( ( Map ) ( sharedWorkingCopies . get ( CompilationUnit . DEFAULT_FACTORY ) ) ) : ( ( Map ) ( sharedWorkingCopies . get ( factory ) ) ) ; if ( perFactoryWorkingCopies == null ) { perFactoryWorkingCopies = new HashMap ( ) ; if ( factory == null ) { sharedWorkingCopies . put ( CompilationUnit . DEFAULT_FACTORY , perFactoryWorkingCopies ) ; } else { sharedWorkingCopies . put ( factory , perFactoryWorkingCopies ) ; } } WorkingCopy workingCopy = ( ( WorkingCopy ) ( perFactoryWorkingCopies . get ( this ) ) ) ; if ( workingCopy != null ) { ( workingCopy . useCount ) ++ ; if ( CompilationUnit . SHARED_WC_VERBOSE ) { System . out . println ( ( "Incrementing<seq2seq4repair_space>use<seq2seq4repair_space>count<seq2seq4repair_space>of<seq2seq4repair_space>shared<seq2seq4repair_space>working<seq2seq4repair_space>copy<seq2seq4repair_space>" + ( workingCopy . toStringWithAncestors ( ) ) ) ) ; } return workingCopy ; } else { workingCopy = ( ( WorkingCopy ) ( this . getWorkingCopy ( pm , factory , problemRequestor ) ) ) ; perFactoryWorkingCopies . put ( this , workingCopy ) ; if ( CompilationUnit . SHARED_WC_VERBOSE ) { <START_BUG> System . out . println ( ( "Creating<seq2seq4repair_space>shared<seq2seq4repair_space>working<seq2seq4repair_space>copy<seq2seq4repair_space>" + ( workingCopy . toDebugString ( ) ) ) ) ; <END_BUG> } JavaElementDelta delta = new JavaElementDelta ( this . getJavaModel ( ) ) ; delta . added ( workingCopy ) ; manager . fire ( delta , DEFAULT_CHANGE_EVENT ) ; return workingCopy ; } } public IJavaElement getWorkingCopy ( ) throws JavaModelException { } public IJavaElement getWorkingCopy ( IProgressMonitor pm , IBufferFactory factory , IProblemRequestor problemRequestor ) throws JavaModelException { } protected boolean hasBuffer ( ) { } public boolean hasChildren ( ) throws JavaModelException { } public boolean isBasedOn ( IResource resource ) { } public boolean isConsistent ( ) throws JavaModelException { } protected boolean isSourceElement ( ) { } public boolean isWorkingCopy ( ) { } public void makeConsistent ( IProgressMonitor pm ) throws JavaModelException { } public void move ( IJavaElement container , IJavaElement sibling , String rename , boolean force , IProgressMonitor monitor ) throws JavaModelException { } public void offsetSourceEndAndChildren ( int amount , IJavaElement child ) { } public void offsetSourceRange ( int amount ) { } protected IBuffer openBuffer ( IProgressMonitor pm ) throws JavaModelException { } protected void openParent ( IProgressMonitor pm ) throws JavaModelException { } protected boolean parentExists ( ) { } public IMarker [ ] reconcile ( ) throws JavaModelException { } public void rename ( String name , boolean force , IProgressMonitor monitor ) throws JavaModelException { } public void restore ( ) throws JavaModelException { } public void triggerSourceEndOffset ( int amount , int nameStart , int nameEnd ) { } public void triggerSourceRangeOffset ( int amount , int nameStart , int nameEnd ) { } public void codeComplete ( int offset , final ICodeCompletionRequestor requestor ) throws JavaModelException { } public IJavaElement rootedAt ( IJavaProject project ) { } }

Fix:
System . out . println ( ( "Creating<seq2seq4repair_space>shared<seq2seq4repair_space>working<seq2seq4repair_space>copy<seq2seq4repair_space>" + ( workingCopy . toStringWithAncestors ( ) ) ) ) ;